Process of chemically modifying proteinaceous materials with aziridine compounds and products thereof



, COMPOUNDS AND PRODUCTS" THEREOF l the use of wool in the textile industry.

PROCESS OF CHEMICALLY MODIFYING PRO- TEIN-ACEOUS MATERIALS WITH AZIRIDINE Giuliana C. Tesoro, Dobbs Ferry, N.Y., assignor to 1. P. Stevens & Co., Inc, New-York, N.Y., a corporation of. Delaware I No Drawing. Filed Apr. 25, 1961, S er..No. 105,285

' i 20 Claims, '(Cl. 8-127.6)

' The present invention relates to a method of chemically modifying proteinaceous materials and to the products thereby obtained, and more particularly polypeptide fibers so as to modify the physicochemical properties of said materials and increase their usefulness. Although the invention has particular application to the treatment of wool in the form of fibers, threads, yarns, fabrics and wool waste, it is also applicable to polypeptides generalas'camel hair, mohair, horse hair, hog bristles, human hair, feathers, and horn), silk fibers, collagen, gelatin,

leather, synthetic polypeptides and the like. I I The application of the present invention for the sbrmkproofing and feltproofing of keratin fibers, and especially and have therefore been used to a limited extent only.

Forexample, the dimensional stability of woolcan be enhanced by treatment with oxidizing agents, but the tensile strength of the wool fiber is severely impaired by such treatments. It is also known to subject wool fibers to alkylation by treating first with a reducing agent which converts the disulfide linkages (S-S) to thiol linkages (--SH) and thereafter treating with a polyfunc! tional halide whereby the thiol groups are linked through new chemical bonds (-fiS-a-lkylene-S). The conditions required for carrying out this reaction are not easily controlled, and although treated wool of good dimensional stability can be obtained by these known processes, the

fibers are weakened by the initial reduction reaction and by the alkaline reagents which must be used as acid acceptors in the alkylation reaction. Generally, processes requiring the conversion of disulfide linkages to thiol as shown above, have similar shortcomings, since the reduction reaction disrupts the fiber structure and impairs fiber properties. Furthermore, the processes which are based on reactions of the disulfide linkage can be applied only to sulfur-containing polypeptides, such as wool, but not to those proteins in which disulfide bonds are absent.

In an etfort to overcome the disadvantages of the proc esses indicated above, other treatments have also been developed. For example, the treatment of protein fibers with various'types of resins has been suggested, but the deposition of resin on or within protein fibers invariably results inan undesirable stiffening of the fibers, and harshness of hand in the textiles and fabrics manufactured from them. fhe amount of resin required to achieve the 1 "U d ta PM 1y, including, in addition to wool, other keratins (such desired results is large, and the insolubilization of the resin which is achieved by a polymerization reaction onv or in the fiber requires curing at elevated temperature, leading to discoloration and other undesirable side eifects. 0n the other hand, polyfunctional reactants which can combine chemically with the unmodified protein (such as, for example, the dicarboxylic acid azides described in US. 'Patent 2,881,046) without significant polymerization and which are eifective in decreasing the solubility of the protein by crosslinking the polypeptide chains, produce only an insignificant decrease in fabric shrinkage even when the amount of reagent combined is large.

Accordingly it would be highly desirable to provide a chemical process whereby the physicochemical properties of proteinaceous materials and particularly in the form of fibers, threads, yarns and fabrics are enhanced and improved.

It is, therefore, an object of this invention to provide a novel process for improving the overall dimensional of said materials. I

A further object of this invention is to provide a novel process of imparting shrinkproofing and feltproofing of keratinfibers, and particularlywool, without producing undesirable side effects such as discoloration, harshness, and a reduction in strength of said fibers. v

A further object of this invention is to provide novel products derived from the aforementioned novel process.

These and other objects of this invention will be apparent from the description which follows.

According to the present invention it has been discovered that the solubility properties and the dimensional stability of polypeptides generally, and of keratin fibers.

in particular can be modified in a highly desirable manner by treatment with certain polyfunctional compounds, which combine chemically with the polypeptide molecule under exceedingly mild conditions without requiring prior reduction or'other pretreatment, without adversely affecting the strength of the fiber, and without causing any discoloration, harshening or other undesirable side effects.

Mor e specifically the novel process of this invention comprises reacting a polypeptide, and preferably a protein I fiber, with a polyfunctional aziridine compound which can be represented by a generic Formula I (I) I m I l C-Rn Q N/ in which R,, R and R are selected from the group consisting of hydrogen and lower alkyl, Q can be an organic or inorganic radical the valence of which is equal .to n, and n has a value of 2 to 3. 1 It has been found that the compounds corresponding to Formula I above have vary- Patented Jan. 12, 1965.

.1 bonds. v

live; Suchv te t d" genericlfFo'rmula III inv' h h. is}; Ra R3. and 'Riari s'e'iectedimmt up consisting of'hydrfofgen and lowerqalkyl, A isfe'n' 1018311161 radicalthe valence of-which. is equal ,to n, and n has a properties .of. the new'compounds represented by generic Formula III arede'scribed in copending application No. 94,720,'file d onjMr h 10, 1961.

responding to theqabove generic Formula ,II I exhibit III is not fully understood, it is'believed that these comi '(a') Thev reagents should possess a functionality greater than one, since by crosslinking of, the polymeric molecules within'the fiber decreased solubility, increased dimenr .sional stability and increased resilience can: be achieved. (b). The reagents should be capable. of forming'oligomers and-polymers containing reactive end groups, 1 since it is known that monomeric crosslinks are not eflicien't; in preventing the shrinkage and felting of protein fibers. 'In effect, then, the reagents should be capable of formingpolyrneric crosslinks' within the fiber structure,

such crosslinks.

(c) The, reagents should possess ,a high degree of mo being attached to the'fiber by covalent r stages, at effectiveness bringing about as; desired results. 1 Compouuds in which the nitrogenato'm'sof the a'z iridine' are amino nitrogens are particularly etfee I} polytunctionalf amino-'a'ziridines. can be reprein which the'R R ',"R R; and n have the meaning de- V fined above and Y represents anorganic radical thev .r valence Of'WhlCh is equal to n and whichdoes not contain any reactive functional groups. The preparation and from thepresenceof suchbri-ttletresins'. 9 v

(d); The reagents should be capable;offreacting\under1 strongly :acidic catalysts, strongly basic'eatalysts 'and i YatQdtemp'eraturesare known to vcause 'fdegrad Q protein fibers, and especially ofwool;

.2 Q sinee'; the use'of'solvents other than; water is hazardous dustrial-processingi y. 'flflie compounds employed in ;thex proc'ess of our' inven- I tion act a ly fulfill the above requirements Examples o'f'compounds which canbe used for the process ofiny' i V f a; the fiber, am harshness of hand invariably res liltsifi-f I 1 mild flconditions, of temperature iand' -eatalysis, since: I

.(e) a The reagents. should preferably ;beter soluble,

and Costly, and aqueous solutionsare preferred a): in:

invention are 1 r-(a).--"Am'ino aziridines prepared Jfror'riIpolyfuhctionalfn9 1 dehyjde s byreaction with ethylene imines 'a'sfshownibyi W Y f xamplfin Equation l wherein R R R are selected from'the grOuPcorisisting of hydrogen'and lowe r 'alkyl, and R' represents an Ialkylene'radical;

Thus, while it has bee'n found "that pol yaziridine com-1' poundsYare-generally etfectivereagents'for improving the f properties ofpolypepticle fibers, and particularly wool whether in; fibe r, thread, yarn or'fabr-ic' form, thosecor- 40- -1 gr'eaterefiiciency than any 4 known compounds, and they y [can eliminate shrinkage and felting, of woolen textiles even 'wh'en usedjini'very smallvamounts. Furthermore, thefstructureof the grouping-Y- can be selectedlso as to; '1 .rnaintain a high degree of; molecular flexibilityinthe poly 'aziridines and in their reaction products with'polypeptides. Although the 'reason' forvthe vast superiority of the 1 f compounds represented bylgeneric Formulas 'II, and III and particularly'ofjthose represented by generic :Formula lecular flexibility and' internalplasticization, so as to avoid the formationofhard, brittle polymericcompouuds in 01-7 (b) Aminoaziridinesa prepared from; ,polyfunctionaL" 7 f h n Pv W y of m q e i a i epoxy compounds by reaction withethyleneiminesas:

'R have the meaning defined above, an 7 (c)-Amino aziridines prepared-by reaction ofjfcompounds containing, conjugated unsaturation with ethylene I imines as .Shown by way of example'in'Equation 3 i r 121 Gam ng-Cam amt 1L1! i I' B1 R1 I RQC 7 05B, l\i--oir,-0H- Reb-cn-omN l Ra- /v I ia I! l Rs wherein R R R have the meaning defined above, R is selected from the group, consisting of hydrogen and methyl, b ha's -a value of zero to i, and R is an organicf radial containing conjugated-unsaturation; a

(d) Amino aziridinesprepared by reaction of com pounds containing activated double bondswith ethylene imines as shown by way of example in Equation 4.f01:-' Y

b'iscrotonate' with ethylene irnine .CH. 7 I a iN-emomsbmimmn y and in Equation 5 for the reaction of ethylene glycol t on, on (liar-411i omeoocrnomoooomorrn j7 H1 H3 H; v H

(e) Amino aziridines prepared byreaction of polyfunctional halides with ethylene imines, as described in copending application No. 94,720 filed Mar; 10,'-l9 6l,

as shown by way of-example and in Equation 6 wherein R R K; have the meaning defined above, X is halogen and R is selected from the group consisung of aralkylene and alkylene radicals. Those compounds the reaction of divinylsulfone with ethylene imine (Besi j with'concentrations ranging from 2 to 4% giw'ng excellent results. The time required for completing the reaction between aziridine compound and the fiber after the drying step, ranges from a few minutes to several hours, depending on the reactivity of the specific polyaziridine compound and .on the reaction temperature. Temperatures rangingjfrom ambient temperatures to about 350 F. can be: used-but temperatures ranging from ambient ternperature to about 300- F. are preferred. 'Some of'the in which the radical R is a polyalkoxy chain, and which can .be represented by a generic Formula fn-tcmmmoixcamm I .Ra' I I the preferred compounds for the process of my invention since they can be prepared from inexpensive and available raw materials. Moreover, they are water soluble, stable in-storage, and react readily with protein fibers 'under mild conditions. In addition they are extraordinarily elfective in eliminating the shrinkage and I felting of wool textiles, and-their chemical structure is i such. that their oligomers and polymers (the formation of whichis believed to precede the chemical reaction of the aziridine groups with the functional groups of the or exposed to moderate temperature for a brief period of time until the reaction between polyaziridine and fiber is completed. A mild process wash designed to remove small amounts of residual reagent completes the treatment. Concentrations of reagent varying from about 1% to about 10% can be employed in the treating solution which R R R5 have the meaning defined above, in hasa value of 2 to 4, and xhasa value of 1 to 50, areand the shrinkage were determined at intervals.

polyaziridine compounds react more rapidly than others.

"In the case of lessreactive compounds, it issometimes.

advantageous to carry out the reaction in the presence of a catalytic amount of acid. The addition of acidic mate- .rial to the treating solution is not usually feasible, since the presence of acid induces rapid polymerization of the polyaziridine compounds in the bath, and reduces the efficiency of the reagent. By pretreating the textile with a low concentration of mineral acid prior to impregnation with the polyaziridine, the catalytic etfect of the acid can be achieved without impairing the stability of the treating solution, and withoutreducing the elfectiveness of the reagent by initiating a polymerization reaction prior to contacting the reagent with the protein fiber.

When the process of this invention is employed to treat Woolen textiles, it can be carried out on the woolen material prior to dyeing. Alternatively the process'of this invention can be carried out after dyeing, as the finishing step, or at intermediate stages of processing.

The procedure employed for the evaluation of the aziridine compounds as shrinkproofing agents and feltproofing agents for keratin fibers was as follows. Samples of wool flannel of various typeswere treated on a laboratory'padder with aqueous solutions of the selected reagent, framed to the original dimensions and dried at moderate temperature (160. to 200 F.) in a laboratory oven. After drying, the reaction was allowed to proceed under varying' conditions of temperatureforvarying periods of time.

The samples were then washed at -1l0 F. in a mild detergent solution'to remove residual unreacted material,

framed to .the originaldimensions and dried. Control samples were handled in identical manner, except that Untreated no reagent was used in the padding solution. controls were also included in the evaluation. The evaluation of initial fabric properties included the observation of appearance and handle and the determinatlon of tensile strength (Ravel strip method ASTM-D- 39-59). The samples were then subjected to repeated launderin'gs (full cycle at F.) in a home-type washing machine, with tumble drying or pressing between launderings. The surface appearance of the fabric samples, Felting and shrinkage of the untreated controls and of the water controls were extremely severe. The treatments invariably reduced the shrinkage and felting, but some compounds proved much more efiicient and effective than The present invention will bemore completely understood by reference to the following examples which illustrate the differences noted above between the untreated controls and fabrics treated by the novel process of this invention. Moreover, itis also apparent that the polyaziridines corresponding to the generic Formulas III and IV above are the most desirable and effective reagents. In each instance all parts and percentages are by weight unless otherwise specified.

EXAMPLE 1 Reagent:

i Cg: CHI

NCH2CH:(0CH2OH2)34N/ on on,

others in achieving control of shrinkage and felting without producing undesirable side effects.

Extrem feltin g.

s of h s TREATMENT EVALUATION [Samples tumble dried de: each laundeiipg] I Perden't Area Cone; Pad Solution,

. Percent Reagent Thre was no discoloration and no harshen WpolSample No.

butrol (2) 1 Fabric pret re ated with aquousfsolufldn 014% sulfuric acid and dried. Room temperature. T

I JOE:

in the course of yt'umb le dry 0H, v l ncmcm( o cmcng a TREATMENT Reaction Time and Temp.

SSS .mhmmmm mmmmww EVALEATION damljsr [Samples tumble dried aftereact x laundering] tially disappeared R 'eagnt:'

Conc. Pad Solution percent: Reagent Wool Sample Fabricpzetreatd with aqueol x ssol ution 4 1% sulfuric acid and dried. r Room temperature. v v I I Reagent:

-' j v cm j; ncmdm(ocmonem TRQATMENT' ConcQPad' v, H Solution, Catalyst Reaction Time Percent Tensile 5 Remarks Percent v and Temp. Wt. St.Werp, "Reagent Increase. Lbs."

2 Watson" [5.3 43 sugmrmrshemng; I 6 24hrs;TR 4.3 41 Soft-hand; 4 -.24hrs. RT L; 2.! 40] D0.

2 do 24111-5. RT L- 1.6 42 4 (I; fif'at 300 F 2.6. 42 2 24hrs.-RT 1.0 4 1 0 None.--....- 41' Untreated. (T 40 Catalyst only.

ted with 1% nqueons solution of sulfurlc'acidanddried. Roomtemperatnre. I

I EVALUATION [Samplestumble dried after each larrndering] '1 Percent Area Shrinkage 1 Wool Samplebl'o. Remarks olo o. v I v 0.0 0. Perfect'smfaee'after laundering.

2.0 v f 3.5[ v ;Contxol (1). 22.0 -,49.6: Extremelelting Control 2 17.5 40.0- Do.

Y -EXAMPLE'4 -f=kegentzj 1 I a e,

l rrcmom(ocmem ,u l 7 v n.

TREATMENT Cone.Pad Percent Tensile Solution, Catalyst Rea ction'lime Wt. St. Warp, Remarks I Percent and Temp. Increase Lbs. I Reagent 241m RT 2'9 :2 Alleam'ples sornewhat 5 41 harsher than rm- 6 4'. 25 42 tlfl86d DQ001119 S0 4 42 after first wash; 0 y 41 Untreated.- 0 1 42 Catalyst e'nly.

EVALUATION eated with 1%- aqueous 80mm or sulfuric; acid and dried. FReomternperatur-e. H

' ssim les tumble dried after each laimdering] Pereent' Area Shrinkage Woel sam le No.

A 0.6 0.5 No felting. B.-- 0.5 2.5 Do. 0... 1.0 7 e9 Do.

9.5 21.0 Conn-01(1)" 22.0 49.5 Extremetelflng. Controlfl) 17.5 40.0 D0.

T115} LW Ncmcmwcmcmm l.

TREATMENT Remarks Reaction Tlme and Temp.

Catalyst Gone. Pad

Percent Reagent Wool Sample Solution,

1 Room tern'peialtima.

} EVALUATION v [Sumples tumble dried after each laundering] .h m .m m B m A m L m 1 m o N m D. m s .m w

' EXAMPLE 6 "Wilh the V H: 'th'z results obtaind are essentially identical to those 'shown above in Example 5. 1

w [EXAMPLE 7' 7 Remarks Percent I Wt.

Increase 70355118 RWELQMZA ZL G CH-OHa l v m TREATMENT Reaction Time and Temp.

I H96 4 7 e Catalyst 7 Reagent:

Cone; Pad Solution,

Reagent 10 Nona 8111's. RT

wb l Sample Percent Water only.

I Fabrlc preti-eated with 1% aqueous solution of sullurln acld land dried. v 1 Boomjam peratme.

- manutacturere recommendations.

EVALUAT O I ing to generic Formulas-I and II. In these experiments, samples of woolen flannel were treated with a 5%-6% solution of the aziridine compound by padding (no catalyst was used), framed to the original dimensions, dried at 160l"-l8'0 F., reacted at room temperature for 24 hours, washed, and dried on frames. The 'shrinkage'was thenidetermined by the procedure outlined above after i [Samples tumble dried aiter eaeh' launderin l-i l eroent krea shrtnklige I i woolsampie No. Remarks 1L 5L 0,;- a9 mailman" 1.5 as Do.-

1.5 so j Do; 2.5 [M Do. 3.5 9.3' Sllght ielting;

0.6 2.2 No felting, but some 1.26- 2.1' Do. I 4.5 11.6' .Some leltlngand harsh- D658; 7 18. 0- 6645 Extreme felting.-

I When the experiment described in Example 7 was re- Table ll peated using other types ofvwoolen fabrics, andfabrics g containing wool blended with synthetic fibers (for expgmntw'ejght' percent .ample a wool/nylon or a wool/ polyester fabric), similar 20 111mm m 36mm excellent results were'obtained. When the treated samples were pressed after each laundering (rather than tumble 3 4 g b 5 dried),v shrinkage and felting were completely eliminated 212 156 I v 3.1 2.5 Reagent re ared from lutsralde- .even after 5 laundermgs g v p I 4.6 28 nhydaggd (ghmmliein 1 l. eagen 1'0 Bl om V 5'1 4 E M 8 i g g 30 4.5 Rionengi d e t hylene imine. :l' ghe following series oftf experiment; VtVlilS caiiried oclllitn in igfi bfi'fiifit' iii $1 13: or er to compare t e e ectrveness o e p0 yazrri es imme- 1.4 corresponding to generlc Formulas III and IV (and 2,0 i Ammo "Mame demonstrated by the treatments of Examples 1 to 7) with -9 Egg j the effectiveness of polyaziridine compounds corresponda l A nitrogenous-formaldehyde resin sold as a shrinkprooflng agent for wool under-the trade marl: Lanaset by the American Cyanamid 00. It wee'applled according to the manufacturers recommendations.

- It is apparent from the experiments described in this example that amino aziridines are generally more effective shrinkproofing agents for wool than amido aziridines. Even the less eifective polyaziridines, however, decreased the shrinkage more significantly than acornmercia'l resin SIIaunderings. The samples were pressed after each 40 r r v laundering. applied by the'recommended. procedure.-

' Tablel- Y CornpbundApplied Generic s Reegent'oiexaniple2 1 I IV .i q tlontw) I I (equation (3)) c 0 E CH,- (ecluet ii m N0H (CH2);OE N C 1 H H lHa u cHlp on, 11

l NCH:CHzSO:CH:CH:N l w i I H3. 6-; CHI," I 7 I CH1 i ucnomcooomomocoomoHN l i v a v I i Ha r.-.--. ..'-r ant-0H 011-011. I

' i NoooomomoooN 8 on,v 0 cm' -r- 1 1' H: I o ,'---cH= w h. Commercial resin None Untreatedcontrol) l A nitrogenous-formaldehyde resin sold see shrinkprooflng agentior wool under the trade mark- Lansset by the American Gyanamid 00. Itwas. applied according to the EXAMPLE 9;

Several monoariridine compounds were applied to H: (Prepared from dodecyl chloride and propylene lmlne) Although the above monoaziridine compounds reacted with the fiber in excellent yields, as indicated by the weight increase, they did not significantly improve the dimensional stability of the fabric. The results of these experiments indicate that polyfunctionality and cross-' linking are required for effective shrinkage control of -woolen fabrics with aziridine compounds.

While the illustrative embodiments of the invention have been described hereinbefore with particularity, it will be understood that various other modifications will be apparent to and can readily be made by those skilled in the 'art without departing from the scope and spirit r of the invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the examples and description set forth herein but rather that the claims be construed as encompassing all the features r of patentable novelty which reside in thevpres'ent invention including all features which would be. treated as patentable 4 equivalents thereof by those'skilled in the art to'which, the invention pertains.

I claim:

1. A process of improving the dimensional stability of proteinaceous materials comprisingreacting said ma- 5 -terials with polyfuuctional aminoaziridine compounds corresponding to the structure! in which R R and R are selectedfrom the group consisting of hydrogenand lower alkyl,.R; is selected from the group consisting of hydrogen, lower alk'yl and j OH, and A is selected from the group consisting of alkylene, hydroxy-substituted alkylene, aralkylene, oxyalkylene, sulfone-containing alkylene, and the residue of a carboxylic acid-ester, the valence of which is equal to nand n has a value of 2 to 3.

2. The process of claim 1 wherein the proteinaceous materialis a keratin fiber. I 3. Theprocess of claim 1 wherein the polyaziridine compound corresponds to the structure:

inwhich' R1, R and R are selected from-thegroup consisting of hydrogen and lower alkyl, m has a value of 2 to 4, and-x has a value of 1 to 50.

'4. The process of claim 1 wherein the polyaziridine compound corresponds to the structure: a

' on, on,

compound corresponds to the structure: E, I v -/VC'H| /NCHaGHr(OCH:CHr)uN\, H1 H! 5. The process of claim 1 wherein the .polyaziridine 6. The process of claim 1 wherein the polyaziridine compound corresponds to the structure: v

I CH2 CH,

\vcrnomwomornmN i m H; i 7. The process of claim 1 wherein the polyaziridine -.compound corresponds to the structure:

CH2. v CH: NCH;CH (OCH;0H:)zN l 7 HI/ H: 8. The process of claim 1 wherein the polyaziridine compound corresponds to the structure: 1

9. The process of claim 1 wherein the. proteinaceous." material consistsatzleastin part of woolen fiber in fiber,-

thread, yarn or fabric form. 1 p

10. The process of claim 9 wherein the reaction between the wool and the aminoaziridine compound is carried out by impregnating the wool with aqueous solution of the reagent, drying and thereafter allowing the reaction to proceed until essentially complete.

11. The processv of claim 9 wherein the reaction between the wool and the aminoaziridine compound is carried out by impregnating the wool with an aqueous solution of the reagent, drying and thereafter allowing the reaction to proceed at temperatures ranging from ambient to 350 F. until essentially complete.

12. The process of claim 9 wherein the wool is used in the formof fabric.

13. The product of claim 1. 14. The'fabric prepared in accordance with claim 10. 15. The process of improving the-dimensional stability of'proteinaceous materialscomprising reacting said materials .with polyaminoaziridine compounds corresponding to the structure: V r

wherein'R R and R are selected from the group. consisting of hydrogen and lower alkyl, and R represents an alkyleue group.

V 16. iTheprocess of improving the dimensional stability or proteinaceous materials comprising reacting said 'material'swith -polyaminoaziridine compounds corresponding 'to the. structure;

wherein R R 'and R are selectedfrom the group consisting of hydrogen and lower alkyl, and R represents an alkylene group.

17'. The process of improving the dimensional stability wherein R R R are selected from the 'g roupconsisting I of hydrogen and lower alkyl, R; is selected from the group consisting of hydrogen and-methyl, b has a'value of to 1, and R? is an organic radical containing conjugated una saturation. j I

of proteinaceous materials comprising reacting said materials with polyaminoaziridine compounds corresponding to the structure:

18. The process of claim 1 wherein the polyamino aziridine compound corresponds to the structure:

20. The process of improving the dimensional stability ofproteinaceous materials comprising reacting said materials with polyaminoaziridine compounds corresponding to the structure:

wherein R R 'and R are selected from the group consisting of hydrogen and lower alkyl and R is selected from the group consisting of aralkylene and alkylene groups. 7

References Cited in the file of this patent UNITED STATES PATENTS 2,831,018 Trieschmann Apr. 15, 1958 2,889,289 Reeves et al. June 2, 1959 2,911,325 Drake et al. Nov. 3, 1959 

1. A PROCESS OF IMPROVING THE DIMENSTIONAL STABILITY OF PROTEINACEOUS MATERIALS COMPRISING REACTING SAID MATERIALS WITH POLYFUNCTIONAL AMINAZIRIDINE COMPOUNDS CORRESPONDING TO THE STRUCTURE: (2-R1,2-R2,3-R3-AZIRIDINO-CH(-R4))N-A IN WHICH R1, R2 AND R3 ARE SELECTED FROM THE GROUP CONSISTING OF HYDROGEN AND LOWER ALKYL, R4 IS SELECTED FROM THE GROUP CONSISTING OF HYDROGEN, LOWER ALKYL AND OH, AND A IS SELECTED FROM THE GROUP CONSISTING OF ALKYLENE, HYDROXY-SUBSTITUTED ALKYLENE, ARALKYLENE, OXYALKYLENE, SULFONE-CONTAINING ALKYLENE, AND THE RESIDUE OF A CARBOXYLIC ACID ESTER, THE VALENCE OF WHICH IS EQUAL TO N AND N HAS A VALUE OF 2 TO
 3. 